iOS 网络编程

iOS 开发中所需的数据基本都是来自网络,网络数据请求是 iOS 编程中必不可少的,应该熟练掌握网络请求.

网络请求方式有 :GET , POST , PUT ,DELETE 等,其中常用的就是 GET,POST . GET 和 POST 请求存在着不同,GET 将数据参数跟在 URL 后面,POST 参数放在 body 中,不可见.

数据请求方式分为同步请求和异步请求,其中常用的是异步请求,异步请求避免了因组线程阻塞而造成的崩溃.这里主要说下异步请求.

1.GET 同步请求 用 NSURLConnection 实现:

　　步骤:建立 request ----> 建立衔接请求数据 ------> 解析数据

代码:

 #pragma mark --- get 同步 ---
 - (IBAction)getOne:(id)sender {
     self.allNewsArray = [[NSMutableArray alloc]init];
     //url 地址
     NSURL *url = [NSURL URLWithString:PATH];
     //请求
     NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];
     //建立衔接请求数据
     NSData *data = [NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil];
     //如果数据不为空就解析
     if (data) {
         NSDictionary *dic = [NSJSONSerialization JSONObjectWithData:data options: error:nil];
         //处理数据,用 model 存储
         for (NSDictionary *dic1 in [dic objectForKey:@"news"]) {
             NewsModel *model = [[NewsModel alloc]init];
             [model setValuesForKeysWithDictionary:dic1];
             [self.allNewsArray addObject:model];
         }

     }
 }

2.GET 异步请求 BLOCK 形式 用 NSURLConnection 实现

 #pragma mark --- get 异步请求 ---
 - (IBAction)getTwo:(id)sender {

     self.allNewsArray = [[NSMutableArray alloc]init];
     //url 地址
     NSURL *url = [NSURL URLWithString:PATH];
     //请求
     NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];
    //默认是 get 方法,如果是 get 方法可以不写
     [NSURLConnection sendAsynchronousRequest:request queue:[NSOperationQueue mainQueue] completionHandler:^(NSURLResponse * _Nullable response, NSData * _Nullable data, NSError * _Nullable connectionError) {
         if (data) {
             NSDictionary *dic = [NSJSONSerialization JSONObjectWithData:data options: error:nil];
             //处理数据,用 model 存储
             for (NSDictionary *dic1 in [dic objectForKey:@"news"]) {
                 NewsModel *model = [[NewsModel alloc]init];
                 [model setValuesForKeysWithDictionary:dic1];
                 [self.allNewsArray addObject:model];
             }
         }

     }];
 }

3.POST 异步请求 BLOCK 形式:用 NSURLConnection 实现

 #pragma mark --- POST 异步 Block 形式 ---
 - (IBAction)POSTBlock:(id)sender {

     NSURL *URL = [NSURL URLWithString:@"http://ipad-bjwb.bjd.com.cn/DigitalPublication/publish/Handler/APINewsList.ashx"];
     NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:URL];

     //制作包体
     NSString *param = @"date=20131129&startRecord=1&len=5&udid=1234567890&terminalType=Iphone&cid=213";

     NSData *data = [param dataUsingEncoding:NSUTF8StringEncoding];

     //设置请求方式
     [request setHTTPMethod:@"POST"];
     //设置 body
     [request setHTTPBody:data];
     [request setTimeoutInterval:];

     //建立连接.请求数据
     [NSURLConnection sendAsynchronousRequest:request queue:[NSOperationQueue mainQueue] completionHandler:^(NSURLResponse * _Nullable response, NSData * _Nullable data, NSError * _Nullable connectionError) {

         //解析数据
         if (data) {
             NSDictionary *dic = [NSJSONSerialization JSONObjectWithData:data options: error:nil];
             //处理数据,用 model 存储
             for (NSDictionary *dic1 in [dic objectForKey:@"news"]) {
                 NewsModel *model = [[NewsModel alloc]init];
                 [model setValuesForKeysWithDictionary:dic1];
                 [self.allNewsArray addObject:model];
             }
         }

     }];
    }

4.POST 异步请求 delegate 形式:用 NSURLConnection 实现

 - (IBAction)POST_Delegate:(id)sender {

     NSURL *URL = [NSURL URLWithString:@"http://ipad-bjwb.bjd.com.cn/DigitalPublication/publish/Handler/APINewsList.ashx"];

     NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:URL];

     //制作包体
     NSString *param = @"date=20131129&startRecord=1&len=5&udid=1234567890&terminalType=Iphone&cid=213";

     NSData *data = [param dataUsingEncoding:NSUTF8StringEncoding];

     //设置请求方式
     [request setHTTPMethod:@"POST"];
     //设置请求 body
     [request setHTTPBody:data];

     //建立连接请求数据
     NSURLConnection *conn = [[NSURLConnection alloc]initWithRequest:request delegate:self];

     //启动请求
     [conn start];
    }

 - (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response{
     NSLog(@"接收到响应");

     self.data = [NSMutableData data];

 }

 #pragma mark --- 接收数据的方法 ---
 - (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data{
     [self.data appendData:data];
 }

 #pragma mark --- 结束传递数据 ---
 - (void)connectionDidFinishLoading:(NSURLConnection *)connection{

     NSDictionary *dic = [NSJSONSerialization JSONObjectWithData:self.data options: error:nil];
     NSLog(@"%@",dic);

 }

 - (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error{

 }

5.GET 异步请求 SESSION 写法

 #pragma mark --- GET Session 写法 ---
 - (IBAction)session:(id)sender {

     //创建 session 对象
     NSURLSession *session = [NSURLSession sharedSession];

     NSURL *URL = [NSURL URLWithString:PATH];

     NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:URL];

     NSURLSessionDataTask *task = [session dataTaskWithRequest:request completionHandler:^(NSData * _Nullable data, NSURLResponse * _Nullable response, NSError * _Nullable error) {

         if(data){
             NSDictionary *dic = [NSJSONSerialization JSONObjectWithData:data options: error:nil];

             NSLog(@"%@",dic);
         }
     }];

     //开始请求 (一定要调用)
     [task resume];
 }

6.POST 异步请求 BLOCK 形式:用 NSURLSession 实现

 - (IBAction)POST_Session:(id)sender {

     NSURL *URL = [NSURL URLWithString:@"http://ipad-bjwb.bjd.com.cn/DigitalPublication/publish/Handler/APINewsList.ashx"];

     NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:URL];

     //制作包体
     NSString *param = @"date=20131129&startRecord=1&len=5&udid=1234567890&terminalType=Iphone&cid=213";

     NSData *data = [param dataUsingEncoding:NSUTF8StringEncoding];

     //设置请求方式
     [request setHTTPMethod:@"POST"];
     //设置请求 body
     [request setHTTPBody:data];

     NSURLSession *session = [NSURLSession sharedSession];
     NSURLSessionDataTask *task = [session dataTaskWithRequest:request completionHandler:^(NSData * _Nullable data, NSURLResponse * _Nullable response, NSError * _Nullable error) {
         NSLog(@"%@",error);

         NSDictionary *dic = [NSJSONSerialization JSONObjectWithData:data options: error:nil];
         NSLog(@"%@",dic);
     }];

     [task resume];
 }